1. Field of the Invention
This invention relates in general to methods for coating materials particularly by evaporation in a vacuum and in particular to a new and useful process for coating an organic material particularly a spectacle glass made of plastic which comprises depositing a deflection reducing coating of chromium on a substrate by evaporation in an oxygen atmosphere under a pressure of from between 4.times.10.sup.-5 and 8.times.10.sup.-5 torr and at a rate of from 0.01 to 0.05 nm per second and to a thickness of from one to 10 nm.
2. Description of the Prior Art
A problem underlying the invention is to deposit reflection reducing coatings on substrates of plastic, for example, on spectacle glasses, which coatings would be sufficiently hard and firmly adherent and capable of resisting atmospheric and chemical influences. In particular, up to the present time, a satisfactory resistance to salt water, as frequently required, for example, for spectacle glasses could be obtained only with difficulties. Extensive laboratory tests have shown that if reflection reducing coating such as usual for glass are deposited on plastics, they are not sufficiently resistant.